The present invention relates to a diazo-type thermosensitive recording material, and more particularly to an improved diazo-type thermosensitive recording material capable of maintaining the integrity of the recorded images without fading.
Thermosensitive recording materials are conventionally used not only as copying sheets for copying books and documents, but also as output recording sheets for use with computers, facsimile apparatus and medical analytical instruments, and for thermosensitive recording type magnetic tickets and thermosensitive recording type labels.
Furthermore, it is considered that thermosensitive recording can also be used for securities, merchandise coupons, entrance tickets, certificates, payment slips and the like by utilizing the property of easy automatic recording. However, thermosensitive recording materials for such uses must be image-fixable in order to maintain the integrity of the recorded images.
Conventionally, as image-fixable thermosensitive recording material, diazo-type thermosensitive recording material are known, which utilize the coloring reaction between a diazonium compound and a coupler. However, with respect to the fading of recording images, the conventional diazo-type thermosensitive recording materials have not yet been sufficiently improved for practical use.